David J. Brennan

Organosilicon derivatives of cyclic and high polymeric phosphazenes

Abstract A new class of compounds is reviewed, the members of which are hybrids of organosilicon and organophosphazene species. They are synthesized either by the reaction of organosilicon halides with organocopper-phosphazene intermediates, or by the interaction of organosilyl or organosiloxy Grignard reagents with chlorophosphazenes. Several of the cyclic trimeric phosphazenes prepared in this way were polymerized by heating to give linear high polymeric phosphazenes with organosilicon side groups.

The synthesis and structure of triphenylsiloxycyclotriphosphazenes

The triphenylsiloxy-substituted cyclotriphosphazenes, N3P3Cl5OSiPh3, gem-N3P3Cl4(OSiPh3)2, N3P3(OSiPh3)6, and N3P3(OPh)5OSiPh3, have been prepared. The synthesis of gem-N3P3Cl4(OSiPh3)2 involves the reaction of (NPCl2)3 with Ph3SiONa to form the intermediates gem-N3P3Cl4(OSiPh3)2(ONa) and gem-N3P3Cl4(ONa)2, which yield gem-N3P3Cl4(OSiPh3)2 when treated with Ph3SiCl. The compounds N3P3Cl5OSiPh3 and N3P3(OSiPh3)0 are formed by the condensation reactions of N3P3Cl5OBun and N3P3(OBun)6, respectively, with Ph3SiCl. The compound N3P3(OPh)5OSiPh3 is synthesized by the reaction between N3P3(OPh)5Cl and Et3SiONa to first give the intermediate N3P3(OPh)5ONa, which yields N3P3(OPh)5OSiPh3 when reacted with Ph3SiCl. The structural characterization and properties of these compounds are discussed. The crystal and molecular structure of gem-N3P3Cl4(OSiPh3)2 has been investigated by single-crystal X-ray diffraction techniques. The crystals are monoclinic with the space group P21/c with a = 16.850(8), b = 12.829(4), c = 18.505(15) A, and β = 101.00(6)° with V = 3927 A3 and Z = 4.